Variable pitch propeller control



Patented July-1,4 1944 1.

UNITED STATES PAT ENT oFFiic E v 7 a I I f 2 ,352,786 p 7 AB El T irRor ifL amma 1 John Hays Hammond, Jr., Gloucester, and George ,A. Colley, Newton Center, Mass. ;-said C'olley assignorto said HammomL -Jr. a

Application March 25, 1940, 'S'erialNo. 325,694

6 Claims.-(Cl. 170- -135.(1

This" invention relates to variable pitch pro pelle'r' systems and more specifically to a system forautomatically varying the pitch of a propeller in accordance with a characteristic of the driving motor. it It has been found that the temperature of the exhaust ga'ses o'f an internal combustion engine,

especially of theTDiesel typefvaries approximately directly" as the shaft horsepower trans mitted'to' the propeller. It is thus possible to ing 'a constant exhaust temperature.

The invention accordingly provides, in one em;-

In turbine and electric propulsion other variables which have a definite relationship'with the transmitted horsepower may be utilized for maintaining this power constant under varying conditions of wind and weather. p The invention further provides means for varying the rate of change of pitch of the propeller blades in accordance with the rate of change of condition, thus causing the device to operate ellicieritly and effectively regardless of the'extent of change required.

An object of the invention is to provide a novel and improved device of the type above indicated which is suited to commercial use on marine vesselsand aircraft.

Other objects will become apparent as the nature of the invention is more fully disclosed. The invention also consists in certain new and original features of construction and combinations of parts hereinafter set 'forth and claimed.

Although the novel features which are believed to becharacteristic of this invention will be more particularly pointed out in the claims appended hereto, the invention itself, as to its objects and advantages, the mode of its operation and the manner of its'organization, may b better understood by referring to the following description taken in connection with the accompanying drawing forming a part thereof, in which the singlefigure illustrates diagrammatically the system as applied to the driving mechanism of a marine vessel.'-'

In-the following'description andin'the claims parts wilkbeid'entified by specific names for convenience, but they are intended to be as generic l maintain a constant power output by maintaintribution valve a; which communicates with the cylinder 21a through ducts; not shown; in the in theiriapplicaticn to sirnilar parts as the art.

any fe esire t ne bums preferably of the Diesel WP? and; i I KQV QQ LWJBh' i qverrionnot shown, for; maintaining; constant; speed of rotation.

1 l s 13. e connected to a variable p c mechanism l8 which may be of any well known and standard construction, such as that manut red by theE he ewy -i e o Zurich, switaerlai d'zthe detailspf which" form no part of the present invention angi areaccordingly not specifically set forth herein. ,j This" mechanism,v

in general fccmprises"aired l9 slidable longitudinallywithinthe shaft Sand connected to control thepitchof'the blades'il3. The rod lBlis actuated by a piston zl in a fluid pressure, cylinder. 21a.

Fluid for actuating "the pistonfi issupplied by a pump 26 through a control ,valve25 and a disshaft I 5.

A motor 2| rotates afworm' 22 operates to move 'the upper en'd..offa floating lever'23',- which, in turn, pivotedio the end of a valve rod 24 whichicontrolsf .the' valve '25. The piston 21 is connected by a rod .28 .t'o-a-collarla which is slidablymounted on'lthe, shaft, l5 and engages;

the lowerendof thefllev'er 23 so that the position of this end oi the lever",cori'esponds .to the pitch of thebladeslSL" I The upper end'of lever 23 is connected by a wire 30 to an indicator. 3 lwhich'shows thepitch at which'the blades 13 [are set; 1 Stops 32am provided for; limiting the. maximum and mini- 31 are providedlfor'theinecessary fluid.

It is to be understoodlthat other ithlcdnt i devices may be employed in place of that referred: to above, for varying the ipitch of thepropel1eri blades l'3"in"r esponseto actuation of the: motor' e is shown for purposes of 21. Apartment. illustration only;

,The' rim' 'fi'ver i211, is preferably of the Diesel engine type, is provided with the usual exhaust pipe 40 in which is mounted a temperaianyingl drawing, the

ture responsivedevice 4| which forms a part of a temperature indicator 42. The temperature indicator 42 is provided with a pointer 44 which registers with a scale 45 graduated, for example, in hundreds of degrees. It is to be understood that other types of direct or remote control exhaust temperature indicating devices may be used if desired.

In accordance with the present invention means is provided to control the-motor. 2| in response to the-. position of the pointer 44. In the embodiment shown a contact 46 is attached to but insulated from the pointer 44. Surrounding the scale 45 and rotatably mounted thereon is a ring 41 to which is attached a segment of aworm gear 48. Meshing with .the gear 48 isa worm 49 which is rotated by means of a. knurled knob 50. ring 41 are a plurality of contact segments 5| to 56 which are selectively engaged by' the contact 46.

The segments 5| and 56 are connected by flexibleconductors to two conductors 6|] and BI which in turn are connected to the reversing windings of the motor 2|. The segments 52 and 53 are connected by flexible conductors to two resistors 66.and B'I-Which are in turn connected to the conductor 66. The segments 54 and 55 are connected by flexible conductors to two resistors I6 and II whichare in-turn connected'to theconductor 6 I. The commonlead of the reversing Mounted on but insulated from the.

windings of the motor 2| is connected-through a battery 12 to the blade -ofa-three position switch vI3. The center. contactof this switch is connected tothe contact 46, the upper contactto the conductor BI and the lower contact to the conductor 60. l t 1 Operation In the operation of the form of the invention shown the pitch of the blades I3 is first set at the normal operating angle for the speed at which it is desired to operate the vessel. The setting of the propeller blades I3 is accomplished by moving the'blade of the switch I3 into the upper or lower position which will cause the motor 2| to move the upper end of the lever '23 to the left or right to increase or decrease the pitch in a well known manner, the angle of' pitch being indicated by the pointer of the indicator 3|. 7

After the vessel has been brought up to the desired speed the temperature of the exhaust under this condition" is indicated by the pointer 44 on the scale 45, which may for example'be 500 degrees. The ring 41 isthen rotated by means of the knurled knob 56 until the insulation between the segments 53 and 54 engages the contact '46; The blade of the switch I3 is then moved into engagement with the center contact.

If the forces against which the vessel is moving should increase such as due to encountering a strong-head wind or running into a heavy sea, the power delivered by the engineZIJ (which is of constant speed due to its governor) would increase thus causing an increase in the'temperatureof the exhaust gases in the exhaust pipe 40, which in turn would affect the indicator 42 causing the pointer 44 to rotate in a clockwise 56, theirno resistance will be thrownin'thecir-"f direction showing an increase of temperature.

72 throughthe resistor 6'I--to the motor 2| causing it to rotate slowly in a direction to move the upper end .of the lever 23 to the right for example. This will move the valve"25to"the right which will allow .fiuid under pressure to 1 pass from the pump 26 to the cylinder 21a by means of the ducts in the shaft vI5. This will actuate the piston 21 which, by means of the rod I9 and the link mechanism will cause the propeller blades I3 to slowly decrease their pitch. This will cause less power to be transmitted from the engine 20, the R. P. M. being maintained constant by means of the governor, thereby decreasing the exhaust temperature until itagaln reaches 500 degrees, at which time the'contact 46 will again rest on the insulation between the segments 53 and 54, thus stopping the motor 2|. If the conditions under which the vessel is operating-should change due to a following wind or other favorable; condition so that less power :is supplied by theengine 20 the temperature of the exhaust would decrease and the reverse acresistor-I I 'ortheresistor 66 will be "thrown in circuit with the motor 2I:'"Asre'sis'tors 'II"' a' n'd'T 66 haveless' resistance than resistors!!! andf'GT lthe motor-2lwill be caused to rotate faster, this changing the propeller pitch more'rapidly't'o t'ake" care of the more rapidly changing-con itions;

If the conditions change so 'qui'ckly' that the" contact 46 engages either segment 51 ersegmem cuitof-the motor'2I 'and itwill 'rotateaitits maximum speed; thus changing the'propellen" pitch at a maximum" rater The stops 32 are" provided so that the propellerpit'ch is prevented from exceeding certain limits beyond'whicli it couldnot'operate efficientlyunder anyco'ndi ti s' .1. 1 lI.. ml.

By-the systems-above described the pitchof the propeller blades I3 is varied to cause the propeller to operate so as to"'m'aintaintheex-" lzaust temperature; and therefore the power 'sup plied from" the engine 20-, constant under varied conditions. The rate of 'cha'n'geof pitch willvary in accordancewith "the change of exhaust ten; perature sothat'with' a gradual change oftem' perature there will be a slow change of p" peller pitch, thus 'preventingviolent,changes of 4' mechanism; disagreeablevibrations" inefiiwhich would cause undue strain'on the driving.

ciency of the propeller but a more in temperature will be promptly andquickly correcte'd' bya 'more" control means.

The"invention" has been specifically deribd'f! as ap ued'tda temperature responsive system actuated by the exhaust temperatures otanjp: e i e qlq und h eo trq m n ay be 7 actuated .by' corresponding characteristics; of.

ternalcombiistion engine. stood, however, that other power sources such as t urbines orelectric motors. While a specific embodimenthas been set rortnror purposes o f il lustrati'on the invention is capable of varioususesan d changes and apparent to a person skillediin t he art,

modifications maybe made there ln as wil l'jbe Although b'nly'a few of the various forinsin g;

which thi Q P QQ ma .PQ l l d have been shcwn herein, it is to be; understood, that H the invention is not to be limited thereto but is only to be restricted in accordance with the scope of the following claims.

What is claimed is:

1. In a system for driving a vessel, a, propeller having adjustable blades, an internal combustion engine having an exhaust, driving said propeller, pitch control mechanism controlling the pitch of said blades, temperature responsive mechanism connected in heat transfer relationship to the exhaust to be actuated by and exclusively as a function of variations in the temperature of the exhaust gases from said engine, and automatic means to maintain a substantially constant exhaust temperature including a reversible control member actuated by said temperature responsive means and connected to cause said pitch control mechanism to increase the pitch of said blades in response to a decrease in exhaust temperature and vice versa.

2. In a system for driving a vessel, a propeller having adjustable blades, an internal combustion engine driving said propeller, pitch control mechanism controlling the pitch of said blades, temperature responsive mechanism connected to be actuated by and exclusively as a function of variations in the temperature of the exhaust gases from said engine, and automatic means to maintain a substantially constant exhaust temperature including a progressive reversible control member actuated by the temperature responsive means and connected to cause said pitch control mechanism to increase the pitch of said blades in response to a decrease in exhaust temperature and vice versa at a speed of operation which varies in accordance with the amplitude of change of temperature, said speed being greater when the amplitude of change in temperature is greater and vice versa, regardless of the direction of such change.

3. In a system for driving a vessel, a propeller having adjustable blades, an internal combustion engine driving said propeller, pitch control mechanism controlling the pitch of said blades, temperature responsive mechanism connected to be actuated by and exclusively as a function of variations in the temperature of the exhaust gases from said engine, automatic means to maintain a substantially constant exhaust temperature including a reversible control member actuated by said temperature responsive means and electrical means connected to cause said reversible control member to increase the pitch of said blades in response to a decrease in exhaust temperature and vice versa.

4. Ina system for driving a vessel, a propeller having adjustable blades, an internal combustion engine driving said propeller, pitch control mechanism controlling the pitch of said blades, temperature responsive mechanism connected to be actuated by and exclusively as a function of variations in the temperature of the exhaust gases from said engine, automatic means to maintain a substantially constant exhaust temperature including a reversible progressive control member having a plurality of electrical contacts and electrical means connected to said contacts to cause said pitch control mechanism to increase the pitch of said blades in response to a decrease in exhaust temperature and Vice versa at a speed of operation which varies in accordance with the amplitude of change of temperature of said gases, said speed being greater whenthe amplitude of change is greater and vice versa, regardless of the direction of such change.

5. The system set forth in claim 1 in which the motor is an internal combustion engine of the Diesel type. V

6. The system set forth in claim '1 in which the propeller is driven at a constant speed.

JOHN HAYS HAMMOND, JR. GEORGE A. COLLEY. 

